Many thanks, it there a risk it could go mouldy? if so what can I do to prevent that?
I don't know, I've only just got some myself. It's used a lot in paladriums and vivariums, and it's a rot proof man made material, so I shouldn't imagine it would attract mould any more than any other surface would. There should be constant water exchange from it as water is drawn out by the mosses and plants you use, and also by evaporation. That said, I believe in paladriums it is common to add springtails, isopods and other bugs to the moss walls to deal with mould and fungus growth.